1. Field of the Invention
The invention relates to a metallic coolant for a metallurgical bath, the composition of the coolant essentially corresponding to that of the bath. The invention also relates to a method of cooling a metallurgical bath using the coolant and to a method of manufacture of the coolant. Finally the invention also provides a use of a further coolant produced in this method of manufacture, in continuous casting.
2. Description of the Prior Art
In metallurgical processes the desired composition of the metal bath is often reached at a temperature which is higher than the temperature at which the metal is to be processed further or at which the liquid metal is to be cast. So in order to achieve the desired temperature, a coolant is fed into the bath in a quantity which corresponds with the desired fall in temperature.
Various demands are made on the coolant, such as:
Its composition must be known and lie between the desired limits so that it corresponds adequately with the composition limits of the bath, in order to prevent the compositional analysis of this bath altering undesirably.
The coolant must have an adequately high dispensed weight to prevent any undesired inclusions.
The dimensions of the coolant particles must lie between set limits so that the coolant is sufficiently manageable.
The coolant must be capable of being dosed smoothly and of being dispensed accurately.
The coolant must be as free as possible from grease, dust, oxide and clinging dirt.
Often shredded metal scrap is used as coolant, for example for steel baths. The scrap may or may not be greatly or slightly deformed in order to make it more manageable.
However, it has been found that there is a need for a metallic coolant which can be dispensed faster and more accurately and has a more dependable cooling effect. For the last requirement it can be noted that if the coolant contains too many small parts, then there is a risk that these stay floating on the bath and provide insufficient cooling effect. On the other hand one of the drawbacks of metal scrap of over-large sizes is that they can block off feed systems which may then become clogged and be unable to be used. This means that other additions essential to the process may not be added to the bath, the bath will not reach the correct composition and the charge will have to be downgraded. Here it should be noted that the dimensions of the feed system have to be kept limited in the case where the coolant is supplied to an installation of which the bath is treated under vacuum, thereby increasing the susceptibility of the installation to clogging.